When Will the U.S. See a Total Solar Eclipse?

There’s a total solar eclipse happening tomorrow. Sadly, it won’t be visible in the continental U.S. Those of you living in Hawaii and parts of Alaska will be able to see a partial solar eclipse. What about the rest of us? We have to wait until 2017 for our show, but it’s going to be spectacular. The path of totality will stretch the entire continental U.S.

But enough about us. Let’s talk about this week’s total solar eclipse.

Tomorrow night (technically Wednesday for Indonesia), the Moon will pass in between the Earth and the Sun. Indonesia and parts of southeast Asia are in for a show. The path of totality, where the Moon completely covers the Sun, will stretch for nearly 100 miles.

Did you know: Tomorrow’s eclipse will be over the day before it began. Yep, really. The total solar eclipse begins Wednesday morning in the Pacific before crossing the international date line and ending on Tuesday afternoon for Hawaii.

Here’s an animation of the entire event.

Those living outside the red line will see a partial eclipse. The further away from the red line you are, the less the Moon will cover the sun. Those of you living in Hawaii could see a partial eclipse of up to 40% of the sun.

Don’t live anywhere near Indonesia, but still want to catch all the solar eclipse action? Slooh and NASA have us covered.

Astronomer Paul Cox gets the awesome job of heading into the Indonesian countryside to cover the total solar eclipse for Slooh.com. Slooh’s live stream kicks off at 6:00 pm EST (3:00 pm PST). At 7:37 pm EST, totality begins. Cox isn’t going solo. A team from the Institute of Astrophysics of the Canary Islands (IAC) will accompany him.

NASA will also be hosting live coverage of tomorrow’s event. Coverage starts at 8 pm with totality occurring from 8:38 to 8:42 pm, according to the NASA page. I know the times are different between NASA and Slooh. I believe the Slooh time is the correct one. Plus, it depends on where NASA and Slooh are set up. That could also be the reason for the time differences.

Total solar eclipses don’t happen all that often, but when they do scientists are ready. On Wednesday morning, NASA scientists will test a new instrument designed to measure polarized light. These measurements will improve the study of electrons in the sun’s corona. Here’s a short video from scientists Nelson Reginald and Natchimuthuk Gopalswamy talking about their experiment.

Total solar eclipses were extremely important in early observations of the sun. During an 1860 eclipse, astronomers saw the first recorded coronal mass ejection. Here’s a sketch of the 1860 eclipse.

Credit: G. Tempel

Today, astronomers use coronagraphs to monitor the sun’s atmosphere. Coronagraphs mimic the effect of a solar eclipse by using a solid disk to block the sun’s surface. But, coronagraphs aren’t perfect.

Because of how light bends around sharp edges, a phenomenon called diffraction, coronagraph disks must be much larger than would otherwise be necessary to block the sun’s face. Coronagraphs, therefore, inherently block much of the sun’s inner atmosphere from scientists’ view – making eclipses a rare chance to observe the lower corona.

Despite all of our technology, tomorrow’s natural event will still teach scientists something about our sun.